N-containing polycyclic aromatic compounds and uses thereof

Abstract

The application belongs to the technical field of organic electroluminescence, and relates to a N-containing polycyclic aromatic compound and application. The application provides a N-containing polycyclic aromatic compound, which generates a multiple resonance effect through interaction of each N atom in a N-containing fused ring. The multiple resonance effect can reduce the Stokes shift of the molecule, narrow the emission spectrum, and increase the rate of intersystem crossing inversion, so that a high-efficiency, high-color-purity luminescent material is obtained.

Description

Technical Field

[0001] This invention belongs to the field of organic electroluminescence technology and relates to an N-containing polycyclic aromatic compound and its applications. Background Technology

[0002] Organic light-emitting devices (OLEDs) are characterized by flexibility, ultralight weight, ultrathinness, low energy consumption, wide viewing angle, active emission, and fast response speed. OLEDs typically consist of an ITO anode, a hole injection layer (HIL), a hole transport layer (HTL), an emissive layer (EML), a hole blocking layer (HBL), an electron transport layer (ETL), an electron injection layer (EIL), and a cathode. Excitons are formed by the combination of holes and electrons injected into the organic film via the positive and negative electrodes. When an exciton returns from an excited state to a stable ground state, it releases energy in the form of light, thus emitting light. Due to the limitations imposed by spin quantum statistics, traditional fluorescent materials can only utilize singlet excitons, which account for 25% of all excitons, during electroluminescence. The remaining 75% of triplet excitons are deactivated through non-radiative transitions, resulting in a maximum quantum efficiency (IQE) of 25%. Phosphorescent metal complexes can utilize both singlet and triplet excitons simultaneously due to the heavy atom effect, enabling the quantum efficiency within the device to reach 100%. However, phosphorescent metal complexes are expensive.

[0003] To improve device performance, OLED luminescent materials have seen rapid development in recent years. Thermally activated delayed fluorescence (TADF) materials are the third generation of organic electroluminescent materials after traditional fluorescence and phosphorescence. These materials generally have a small singlet-triplet energy level difference (ΔEst), and emit light by converting triplet excitons into singlet excitons through the intersystem crossing inversion (RISC) process, with a theoretical internal quantum efficiency of up to 100%. However, these materials typically contain typical donor-acceptor units, effectively separating the highest occupied orbital (HOMO) and lowest unoccupied orbital (LUMO), resulting in a small ΔEst. However, these donor-acceptor materials exhibit significant vibrational lag in the excited state, with a large Stokes shift, leading to a broad emission spectrum, typically with a full width at half maximum (FWHM) greater than 60 nm. For OLED displays, although the spectrum can be narrowed using optical techniques such as filters or microcavity effects to obtain a high-color-purity emission spectrum, these methods significantly increase power consumption and product cost, and also reduce actual luminous efficiency, resulting in energy waste. To obtain materials with narrow emission bands, Takuji Hatakeyama first reported DABNA-1 and DABNA-2, two boron-intercalated polycyclic aromatic compounds with multiple resonances (MLIs), achieving a full width at half maximum (FWHM) of 28 nm and CIEy values ​​of 0.09 and 0.03, respectively. Since then, boron-containing multiple resonance materials have seen rapid development. Although boron-containing multiple resonance materials can achieve high efficiency and narrow spectral emission, the difficulty and low yield of introducing boron atoms have hindered the industrialization of these products. Developing non-boron-type multiple resonance compounds has become an important research topic in the industry. Summary of the Invention

[0004] To address the aforementioned problems, the present invention aims to provide an N-containing polycyclic aromatic compound and its applications. This compound is a non-B-type multiple resonance compound, a host material with bipolar characteristics, and has a simple device fabrication process, thereby improving the photoelectric performance of phosphorescent devices.

[0005] On one hand, the present invention relates to an N-polycyclic aromatic compound, the structure of which is shown in formula (I):

[0006]

[0007] Where X1, X2, and X3 are N or C respectively;

[0008] At least one of X1, X2, and X3 is N;

[0009] R1, R2, R3, and R4 are hydrogen atoms, deuterium atoms, or methyl groups, respectively.

[0010] L is a single bond, aryl, or heteroaryl;

[0011] Ar is an electron-withdrawing group or an electron-donating group, whether substituted or unsubstituted. Preferably, L is phenyl or naphthyl. In particular, X1, X2, and X3 cannot all be N.

[0012] Furthermore, in the N-containing polycyclic aromatic compounds provided by the present invention, the electron-withdrawing groups include: substituted or unsubstituted triazine, substituted or unsubstituted pyrimidinyl, substituted or unsubstituted pyridinyl, substituted or unsubstituted pyrazinyl, substituted or unsubstituted o-phenanthrolinel, substituted or unsubstituted triphenylphosphine, substituted or unsubstituted boron-containing ligands, substituted or unsubstituted quinoxalinyl, substituted or unsubstituted sulfoxide, substituted or unsubstituted spirodifluorene, and substituted or unsubstituted biphenyl.

[0013] Furthermore, in the N-containing polycyclic aromatic compounds provided by the present invention, the electron-donating groups include: substituted or unsubstituted carbazolyl, substituted or unsubstituted amino derivatives, substituted or unsubstituted fluorenyl, substituted or unsubstituted furanyl, substituted or unsubstituted acridinel, and substituted or unsubstituted phenoxazinel.

[0014] Furthermore, in the N-containing polycyclic aromatic compounds provided by the present invention, at least one hydrogen atom bonded to C is replaced by a deuterium atom.

[0015] Furthermore, the N-polycyclic aromatic compounds provided by this invention include any one of compounds 1 to 84, with the following structure:

[0016]

[0017]

[0018]

[0019] On the other hand, the present invention relates to the application of intermediate A or intermediate B in the preparation of the above-mentioned N-containing polycyclic aromatic compounds, wherein the structures of intermediate A and intermediate B are as follows:

[0020]

[0021] On the other hand, the present invention relates to the application of the above-mentioned N-containing polycyclic aromatic compounds in luminescent materials or host materials.

[0022] On the other hand, the present invention relates to an organic electroluminescent device, comprising a light-emitting layer, the light-emitting layer comprising the above-mentioned N-containing polycyclic aromatic compounds.

[0023] The technical solution provided by this invention has at least the following beneficial effects or advantages:

[0024] This invention provides a class of N-containing polycyclic aromatic compounds that generate multiple resonance effects through the interaction of individual N atoms, resulting in high-performance, narrow-spectrum emission, and structurally diverse MR-TADF materials. Furthermore, this class of N-containing polycyclic aromatic compounds, through modification with auxiliary groups, can yield bipolar materials that exhibit excellent performance as phosphorescent host materials or luminescent materials. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of the organic electroluminescent element provided in the device embodiment of the present invention.

[0026] Explanation of reference numerals in the attached figures: 1 is the substrate, 2 is the anode layer, 3 is the hole injection layer, 4 is the first hole transport layer, 5 is the second hole transport layer, 6 is the light-emitting layer, 7 is the hole blocking layer, 8 is the electron transport layer, 9 is the electron injection layer, and 10 is the cathode layer. Detailed Implementation

[0027] The technical solution of the present invention will be described below with reference to the embodiments. However, the present invention is not limited to the following embodiments.

[0028] To enable those skilled in the art to better understand and implement the technical solutions of the present invention, the present invention will be further described below in conjunction with specific embodiments and accompanying drawings. However, the embodiments described are not intended to limit the present invention.

[0029] Unless otherwise specified, the experimental and detection methods described in the following embodiments are conventional methods; unless otherwise specified, the reagents and materials are commercially available.

[0030] Example 1

[0031] This embodiment provides a method for preparing intermediate A.

[0032]

[0033] Under nitrogen protection, compound A-1 (105.0 g, 576.2 mmol), compound A-2 (209.0 g, 576.2 mmol), sodium tert-butoxide (166.1 g, 1.73 mol), bis(triphenylphosphine palladium) (1.5 g, 2.9 mmol), and xylene (2.5 L) were added sequentially to a reaction flask, and the mixture was heated under reflux for 8 h. After the reaction was complete, the system was cooled to room temperature. The reaction solution was washed with water until neutral, dried over anhydrous magnesium sulfate, concentrated, and recrystallized to give 141.1 g of white solid A-3, with a yield of 58.7%.

[0034] Under nitrogen protection, intermediate A-3 (140.0 g, 335.6 mmol), potassium carbonate (139.2 g, 1.0 mol), bis(triphenylphosphine palladium) (8.6 g, 16.8 mmol), and DMF (1.5 L) were added sequentially to a reaction flask. After the reaction was complete, the system was cooled to room temperature and poured into a large amount of water with stirring. A white precipitate formed, which was collected by suction filtration. The filter cake was washed successively with water and ethanol. Finally, the obtained filter cake was dissolved in an appropriate amount of toluene / ethanol and recrystallized to give 42.2 g of intermediate A as a white solid, with a yield of 49.2%.

[0035] Example 2

[0036] This embodiment provides a method for preparing intermediate B.

[0037]

[0038] Under nitrogen protection, intermediates A-1 (50.0 g, 274.4 mmol), B-1 (99.5 g, 274.4 mmol), cesium carbonate (134.1 g, 411.6 mmol), and DMF (800 mL) were added sequentially to a reaction flask, and the mixture was heated under reflux for 8 h. After the reaction was complete, the system was cooled to room temperature and poured into a large amount of water with stirring. A white precipitate formed, which was collected by suction filtration. The filter cake was washed successively with water and ethanol. Finally, the obtained filter cake was dissolved in an appropriate amount of toluene / ethanol and recrystallized (volume ratio 2:3) to give 83.3 g of white solid B-2, with a yield of 72.6%.

[0039] Under nitrogen protection, intermediate B-2 (80.0 g, 191.3 mmol), potassium carbonate (79.3 g, 574.0 mmol), bis(triphenylphosphine palladium) (4.9 g, 9.6 mmol), and DMF (800 mL) were added sequentially to a reaction flask. After the reaction was complete, the system was cooled to room temperature and poured into a large amount of water with stirring. A white precipitate formed, which was collected by suction filtration. The filter cake was washed successively with water and ethanol. Finally, the obtained filter cake was dissolved in an appropriate amount of toluene / ethanol and recrystallized to obtain 20.7 g of intermediate B as a white solid, with a yield of 42.3%.

[0040] Example 3

[0041] This embodiment provides the preparation of compound 3.

[0042]

[0043] Under nitrogen protection, intermediate A (10.0 g, 39.2 mmol), compound 3-1 (15.8 g, 41.1 mmol), sodium tert-butoxide (11.3 g, 117.5 mmol), bis(triphenylphosphine palladium) (0.1 g, 0.2 mmol), and xylene (200 mL) were added sequentially to a reaction flask, and the mixture was heated to reflux for 8 h. After the reaction was complete, the system was cooled to room temperature. The reaction solution was washed with water until neutral, dried over anhydrous magnesium sulfate, concentrated, and recrystallized from toluene / ethanol (volume ratio 2:3) to give 14.4 g of compound 3 as a white solid, with a yield of 65.9%.

[0044] The mass spectrometry results of the obtained sample were: HR-MS (APCI): m / z 560.3427 [M+H] + Calculated values ​​of C41H25N3 (%): C, 87.99%; H, 4.50%; N, 7.51%; Measured values: C, 88.05%; H, 4.49%; N, 7.55%.

[0045] Example 4

[0046] This embodiment provides the preparation of compound 9.

[0047]

[0048] Under nitrogen protection, intermediate A (10.0 g, 39.2 mmol), compound 9-1 (16.7 g, 41.1 mmol), sodium tert-butoxide (11.3 g, 117.5 mmol), bis(triphenylphosphine palladium) (0.1 g, 0.2 mmol), and xylene (200 mL) were added sequentially to a reaction flask, and the mixture was heated to reflux for 8 h. After the reaction was complete, the system was cooled to room temperature. The reaction solution was washed with water until neutral, dried over anhydrous magnesium sulfate, concentrated, and recrystallized from toluene / ethanol (volume ratio 2:3) to give 13.0 g of compound 9 as a white solid, with a yield of 57.2%.

[0049] The mass spectrometry results of the obtained sample were: HR-MS (APCI): m / z 580.1637 [M+H] + Calculated values ​​of C40H29N5 (%): C, 82.88%; H, 5.04%; N, 12.08%; Measured values: C, 82.93%; H, 5.01%; N, 12.03%.

[0050] Example 5

[0051] This embodiment provides the preparation of compound 10.

[0052]

[0053] Under nitrogen protection, intermediate A (10.0 g, 39.2 mmol), compound 10-1 (16.7 g, 41.1 mmol), sodium tert-butoxide (11.3 g, 117.5 mmol), bis(triphenylphosphine palladium) (0.1 g, 0.2 mmol), and xylene (200 mL) were added sequentially to a reaction flask, and the mixture was heated to reflux for 8 h. After the reaction was complete, the system was cooled to room temperature. The reaction solution was washed with water until neutral, dried over anhydrous magnesium sulfate, concentrated, and recrystallized from toluene / ethanol (volume ratio 2:3) to give 12.2 g of compound 10 as a white solid, with a yield of 53.7%.

[0054] The mass spectrometry results of the obtained sample are as follows: HR-MS (APCI): m / z 580.4531 [M+H] + Calculated values ​​of C41H34BN3 (%): C, 84.97%; H, 5.91%; N, 7.25%; Measured values: C, 875.07%; H, 5.89%; N, 7.22%.

[0055] Example 6

[0056] This embodiment provides the preparation of compound 13.

[0057]

[0058] Under nitrogen protection, intermediate A (10.0 g, 39.0 mmol), compound 9-1 (16.6 g, 41.0 mmol), sodium tert-butoxide (11.2 g, 117.1 mmol), bis(triphenylphosphine palladium) (0.1 g, 0.2 mmol), and xylene (200 mL) were added sequentially to a reaction flask, and the mixture was heated to reflux for 8 h. After the reaction was complete, the system was cooled to room temperature. The reaction solution was washed with water until neutral, dried over anhydrous magnesium sulfate, concentrated, and recrystallized from toluene / ethanol (volume ratio 2:3) to give 12.0 g of compound 13 as a white solid, with a yield of 52.9%.

[0059] The mass spectrometry results of the obtained sample are as follows: HR-MS (APCI): m / z 581.3512 [M+H] + Calculated values ​​of C39H28N6 (%): C, 80.67%; H, 4.86%; N, 14.47%; Measured values: C, 80.69%; H, 4.89%; N, 14.39%.

[0060] Example 7

[0061] This embodiment provides the preparation of compound 21.

[0062]

[0063] Under nitrogen protection, intermediate A (10.0 g, 39.2 mmol), compound 21-1 (8.8 g, 41.1 mmol), sodium tert-butoxide (11.3 g, 117.5 mmol), bis(triphenylphosphine palladium) (0.1 g, 0.2 mmol), and xylene (200 mL) were added sequentially to a reaction flask, and the mixture was heated to reflux for 8 h. After the reaction was complete, the system was cooled to room temperature. The reaction solution was washed with water until neutral, dried over anhydrous magnesium sulfate, concentrated, and recrystallized from toluene / ethanol (volume ratio 2:3) to give 11.0 g of compound 21 as a white solid, with a yield of 72.6%.

[0064] The mass spectrometry results of the obtained sample are as follows: HR-MS (APCI): m / z 388.2437 [M+H] + Calculated values ​​of C27H21N3 (%): C, 83.69%; H, 5.46%; N, 10.84%; Measured values: C, 83.66%; H, 5.49%; N, 10.86%.

[0065] Example 8

[0066] This embodiment provides the preparation of compound 34.

[0067]

[0068] Under nitrogen protection, intermediate A (10.0 g, 39.0 mmol), compound 34-1 (17.8 g, 41.0 mmol), sodium tert-butoxide (11.2 g, 117.1 mmol), bis(triphenylphosphine palladium) (0.1 g, 0.2 mmol), and xylene (200 mL) were added sequentially to a reaction flask, and the mixture was heated under reflux for 8 h. After the reaction was complete, the system was cooled to room temperature. The reaction solution was washed with water until neutral, dried over anhydrous magnesium sulfate, concentrated, and recrystallized from toluene / ethanol (volume ratio 2:3) to give 15.5 g of compound 34 as a white solid, with a yield of 65.1%.

[0069] The mass spectrometry results of the obtained sample were: HR-MS (APCI): m / z 610.3157 [M+H] + Calculated values ​​of C42H35N5 (%): C, 82.73%; H, 5.78%; N, 11.48%; Measured values: C, 82.76%; H, 5.72%; N, 11.53%.

[0070] Example 9

[0071] This embodiment provides the preparation of compound 37.

[0072]

[0073] Under nitrogen protection, intermediate A (10.0 g, 39.2 mmol), compound 37-1 (17.9 g, 41.1 mmol), sodium tert-butoxide (11.3 g, 117.5 mmol), bis(triphenylphosphine palladium) (0.1 g, 0.2 mmol), and xylene (200 mL) were added sequentially to a reaction flask, and the mixture was heated under reflux for 8 h. After the reaction was complete, the system was cooled to room temperature. The reaction solution was washed with water until neutral, dried over anhydrous magnesium sulfate, concentrated, and recrystallized from toluene / ethanol (volume ratio 2:3) to give 14.8 g of compound 37 as a white solid, with a yield of 61.7%.

[0074] The mass spectrometry results of the obtained sample were: HR-MS (APCI): m / z 611.2673 [M+H] + Calculated values ​​of C43H38N4 (%): C, 84.55%; H, 6.27%; N, 9.17%; Measured values: C, 84.62%; H, 6.19%; N, 9.11%.

[0075] Example 10

[0076] This embodiment provides the preparation of compound 41.

[0077]

[0078] Under nitrogen protection, intermediate A (10.0 g, 39.2 mmol), compound 41-1 (11.2 g, 41.1 mmol), sodium tert-butoxide (11.3 g, 117.5 mmol), bis(triphenylphosphine palladium) (0.1 g, 0.2 mmol), and xylene (200 mL) were added sequentially to a reaction flask, and the mixture was heated to reflux for 8 h. After the reaction was complete, the system was cooled to room temperature. The reaction solution was washed with water until neutral, dried over anhydrous magnesium sulfate, concentrated, and recrystallized from toluene / ethanol (volume ratio 2:3) to give 11.3 g of compound 41 as a white solid, with a yield of 64.3%.

[0079] The mass spectrometry results of the obtained sample were: HR-MS (APCI): m / z 448.1067 [M+H] + Calculated values ​​of C32H21N3 (%): C, 85.88%; H, 4.73%; N, 9.39%; Measured values: C, 85.86%; H, 4.69%; N, 9.43%.

[0080] Example 11

[0081] This embodiment provides the preparation of compound 42.

[0082]

[0083] Under nitrogen protection, intermediate A (10.0 g, 39.2 mmol), compound 42-1 (13.2 g, 41.1 mmol), sodium tert-butoxide (11.3 g, 117.5 mmol), bis(triphenylphosphine palladium) (0.1 g, 0.2 mmol), and xylene (200 mL) were added sequentially to a reaction flask, and the mixture was heated to reflux for 8 h. After the reaction was complete, the system was cooled to room temperature. The reaction solution was washed with water until neutral, dried over anhydrous magnesium sulfate, concentrated, and recrystallized from toluene / ethanol (volume ratio 2:3) to give 12.6 g of compound 42 as a white solid, with a yield of 65.1%.

[0084] The mass spectrometry results of the obtained sample were: HR-MS (APCI): m / z 497.2165 [M+H] + Calculated values ​​of C35H20N4 (%): C, 84.66%; H, 4.06%; N, 11.28%; Measured values: C, 84.59%; H, 4.09%; N, 11.20%.

[0085] Example 12

[0086] This embodiment provides the preparation of compound 57.

[0087]

[0088] Under nitrogen protection, intermediate A (10.0 g, 39.2 mmol), compound 57-1 (16.1 g, 41.1 mmol), sodium tert-butoxide (11.3 g, 117.5 mmol), bis(triphenylphosphine palladium) (0.1 g, 0.2 mmol), and xylene (200 mL) were added sequentially to a reaction flask, and the mixture was heated under reflux for 8 h. After the reaction was complete, the system was cooled to room temperature. The reaction solution was washed with water until neutral, dried over anhydrous magnesium sulfate, concentrated, and recrystallized from toluene / ethanol (volume ratio 2:3) to give 13.8 g of compound 57 as a white solid, with a yield of 62.2%.

[0089] The mass spectrometry results of the obtained sample were: HR-MS (APCI): m / z 559.1382 [M+H] + Calculated values ​​of C38H18N6D4 (%): C, 81.71%; H, 3.25%; N, 15.04%; Measured values: C, 81.86%; H, 3.19%; N, 15.18%.

[0090] Example 13

[0091] This embodiment provides the preparation of compound 74.

[0092]

[0093] Under nitrogen protection, intermediate A (10.0 g, 39.2 mmol), compound 74-1 (18.0 g, 41.1 mmol), sodium tert-butoxide (11.3 g, 117.5 mmol), bis(triphenylphosphine palladium) (0.1 g, 0.2 mmol), and xylene (200 mL) were added sequentially to a reaction flask, and the mixture was heated to reflux for 8 h. After the reaction was complete, the system was cooled to room temperature. The reaction solution was washed with water until neutral, dried over anhydrous magnesium sulfate, concentrated, and recrystallized from toluene / ethanol (volume ratio 2:3) to give 13.5 g of compound 74 as a white solid, with a yield of 56.2%.

[0094] The mass spectrometry results of the obtained sample were: HR-MS (APCI): m / z 605.3523 [M+H] + Calculated values ​​of C43H32N4D4 (%): C, 85.40%; H, 5.33%; N, 9.26%; Measured values: C, 85.53%; H, 5.29%; N, 9.12%.

[0095] Other N-containing polycyclic aromatic compounds provided in this application can be prepared by referring to Examples 1 to 13 above.

[0096] Device Example 1

[0097] This embodiment of the device provides an organic electroluminescent device, the structure of which is as follows: Figure 1 As shown, the substrate 1, anode layer 2, hole injection layer 3, first hole transport layer 4, second hole transport layer 5, light-emitting layer 6, hole blocking layer 7, electron transport layer 8, electron injection layer 9, and cathode layer 10 are stacked sequentially.

[0098] Specifically, the anode layer 2 is made of indium tin oxide (ITO) with a high work function; the hole injection layer 3 is made of HATCN with a thickness of 5 nm; the first hole transport layer 4 is made of HT1 with a thickness of 60 nm; the second hole transport layer 5 is made of HT2 with a thickness of 15 nm; the light-emitting layer 6 uses compound 3 as the host material and GD01 as the light-emitting material, with a doping mass ratio of 6% and a thickness of 30 nm; the hole blocking layer 7 is made of HB with a thickness of 10 nm; the electron transport layer 8 is made of ET-1 with a thickness of 35 nm; the electron injection layer 9 is made of Liq with a thickness of 2 nm; and the cathode layer is made of Al with a thickness of 100 nm.

[0099] The basic material structures used in each functional layer of the device are as follows:

[0100]

[0101] The specific fabrication steps of the above-mentioned organic electroluminescent device are as follows:

[0102] 1) Clean the ITO anode on the transparent glass or plastic substrate by ultrasonic cleaning with deionized water, acetone and ethanol for 20 minutes each, and then perform plasma treatment in an oxygen atmosphere for 5 minutes.

[0103] 2) On the ITO anode layer, a hole injection layer material HATCN with a thickness of 5nm is deposited by vacuum evaporation. This layer serves as the hole injection layer.

[0104] 3) Hole transport material HT1 with a thickness of 60nm is deposited on the hole injection layer by vacuum evaporation. This layer serves as the first hole transport layer.

[0105] 4) Hole transport material HT2 with a thickness of 15nm is deposited on the first hole transport layer HT1 by vacuum evaporation. This layer serves as the second hole transport layer.

[0106] 5) On the second hole transport layer, a light-emitting layer is co-deposited by vacuum evaporation, using compound 3 as the host material and GD01 as the light-emitting material, with a doping mass ratio of 6% and a thickness of 30nm.

[0107] 6) Hole blocking material HB with a thickness of 10nm is deposited on the light-emitting layer by vacuum evaporation. This layer serves as the hole blocking layer.

[0108] 7) Electron transport material ET-1 with a thickness of 35nm is deposited on the hole blocking layer by vacuum evaporation. This layer serves as the electron transport layer.

[0109] 8) On the electron transport layer, the electron injection material Liq is deposited by vacuum evaporation with a thickness of 2nm. This layer serves as the electron injection layer.

[0110] 9) On the electron injection layer, cathode Al is deposited by vacuum evaporation with a thickness of 100 nm. This layer is used as the cathode conductive electrode.

[0111] Device Example 2

[0112] The implementation process is the same as in Device Example 1, except that the main material is Compound 9.

[0113] Device Example 3

[0114] The implementation process is the same as in Device Example 1, except that the main material is mCBP, the luminescent material is Compound 10, and the doping concentration is 5%.

[0115] Device Example 4

[0116] The implementation process is the same as in Device Example 1, except that the main material is Compound 13.

[0117] Device Example 5

[0118] The implementation process is the same as in Device Example 3, except that the luminescent material is Compound 21.

[0119] Device Example 6

[0120] The implementation process is the same as in Device Example 3, except that the luminescent material is compound 37.

[0121] Device Example 7

[0122] The implementation process is the same as in Device Example 3, except that the luminescent material is compound 41.

[0123] Device Example 8

[0124] The implementation process is the same as in Device Example 3, except that the luminescent material is compound 42.

[0125] Device Example 9

[0126] The implementation process is the same as in Device Example 1, except that the main material is Compound 57.

[0127] Device Example 10

[0128] The implementation process is the same as in Device Example 3, except that the luminescent material is Compound 74.

[0129] Comparative Example 1

[0130] The implementation process is the same as in Device Example 1, except that mCBP is used as the main material.

[0131] Comparative Example 2

[0132] The implementation process is the same as in Device Example 3, except that the luminescent material is BD-1.

[0133] The T1 energy level and HOMO and LUMO energy levels of some of the compounds provided in the above embodiments and existing materials were quantitatively calculated, and the results are shown in Table 1:

[0134] Table 1. HOMO, LUMO, and triplet energy values ​​of the compounds of this invention.

[0135]

[0136]

[0137] Note: The highest molecular occupied orbital (HOMO) and the lowest molecular unoccupied orbital (LUMO), and the T1 value are data calculated by Gaussian simulation software.

[0138] As shown in Table 1, the compounds disclosed in this invention have suitable HOMO / LUMO, and these compounds are suitable for use as luminescent materials or phosphorescent hosts.

[0139] The constituent components of the different devices prepared in Examples 1-10 and Comparative Examples 1-2 of the present invention are shown in Table 2.

[0140] Table 2. Comparison of the constituent components of organic electroluminescent devices in various device embodiments.

[0141]

[0142]

[0143] The cathodes and anodes of each group of organic electroluminescent devices were connected using a known driving circuit. The voltage-efficiency-brightness relationship of the OLED devices was tested using a Keithley 2400 power supply and a PR670 photometer according to standard methods. The test results are shown in Table 3.

[0144] Table 3. Performance results of organic electroluminescent devices in each group

[0145]

[0146]

[0147] As shown in Table 3, the compounds provided by this invention exhibit excellent performance when used as luminescent materials in OLED devices. Compared to the phosphorescent host compound mCBP in the prior art, the compounds of this invention possess bipolar characteristics, resulting in a significant improvement in device efficiency. Compared to the host material mCBP in Comparative Example 1, the device prepared from compound 57 in Example 9 shows a 10.29% increase in efficiency. As a luminescent material, compared to the structure of the existing material BD-1, the compounds of this invention do not contain boron (B), making the synthesis process easier and yielding higher results, and resulting in superior device performance. For example, compound 74 in Device Example 10, as a blue light material, shows a 17% increase in luminescent efficiency, a narrower emission spectrum, and higher color purity compared to BD-1 in Comparative Example 2. This demonstrates that non-B-type materials can also achieve multiple resonance effects, improving device color purity and efficiency. Given their excellent material properties, the above compounds show promising application prospects in OLED devices.

[0148] As described above, the present invention can be well implemented. The above embodiments are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, all kinds of changes and improvements made by those skilled in the art to the technical solutions of the present invention should fall within the protection scope defined by the present invention.

Claims

1. A polycyclic aromatic compound containing N rings, characterized in that, Choose from any of the following structures: 。 2. The use of intermediate A or intermediate B in the preparation of the N-containing polycyclic aromatic compound of claim 1, characterized in that, The structures of intermediate A and intermediate B are as follows: 。 3. The application of the N-containing polycyclic aromatic compound as described in claim 1 in the luminescent layer material.

4. The application according to claim 3, characterized in that, The light-emitting layer material is the main material.

5. An organic electroluminescent device, comprising a light-emitting layer, characterized in that, The light-emitting layer comprises the N-containing polycyclic aromatic compound as described in claim 1.

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